THE HAGUE, Netherlands — In a cautious first step toward unlocking 30 years of tense relations, senior U.S. diplomat Richard Holbrooke had a brief but cordial meeting with Iran's deputy foreign minister Tuesday at an international conference on Afghanistan.

The rare diplomatic approach was the first official face-to-face interplay between the Obama administration and the Iranian regime. U.S. Secretary of State Hillary Rodham Clinton cautioned that the brief talks between Holbrooke and Iranian diplomat Mehdi Akhundzadeh were cordial but not "substantive."

"They agreed to stay in touch," Clinton said at the close of a one-day conference on Afghan security and development that was designed partly to allow the diplomatic turn with Iran. She told NBC News, "We think there is room for more engagement with Iran going forward."

The meeting between Holbrooke, President Barack Obama's hand-picked Afghanistan envoy, and Akhundzadeh came on the sidelines of a session aimed at improving Afghanistan's future prospects. Akhundzadeh pledged to help the reconstruction of its neighbor, but he criticized U.S. plans to send more troops into Afghanistan.

The gathering was being closely watched for signs that the U.S. and Iran can work together on a common problem after years of hostility. The two countries cooperated at a distance in 2001 and 2002 after U.S.-led forces ousted Afghanistan's Taliban government.

The U.S. and Iran have been estranged for 30 years, since young Iranians stormed the U.S. Embassy in Tehran and took more than 50 Americans hostage for 444 days. Representatives of the two nations are rarely even in the same room with one another, but they have had accidental-on-purpose public meetings on the sidelines of other international gatherings.

Letter for IranThe face-to-face pleasantries, along with a diplomatic letter hand-delivered to the Iranian delegation by a U.S. official, were carefully calibrated overtures from the Obama administration aimed at testing the clerical regime's willingness to take larger steps.

Video: We shouldn't 'ignore' Iran
Afghanistan and Iran share nearly 600 miles of border, and Clinton said the United States and Afghanistan share concern over the flow of drugs into Iran.

"We will look for ways to cooperate with them and I think the fact that they came today, that they intervened today, is a promising sign that there will be future cooperations," she said.

The diplomatic letter, which Clinton and aides would not describe in detail, asked for Iran's help in releasing or lifting travel restrictions on two American women in Iran, and information on a man missing for two years since traveling to Iran on business.

The cases and the American position on them were known. What is different was the Obama administration's decision to approach Iran directly, instead of using a go-between.

Information or help from Tehran "would constitute a humanitarian gesture by the Iranians in keeping with the spirit of renewal and generosity that marks the Persian new year," Clinton said.

Obama recently sent an unusual video message to mark the Iranian new year in March.

Week of diplomatic gatheringsThe conference opens a week of diplomatic gatherings in Europe where Obama is also expected to try for a fresh start in the bumpy U.S. relationship with Russia. Numerous U.S. allies have encouraged a better relationship with oil-rich and strategic Iran.

As a candidate, Obama said he would reach out to Iran, and even hold direct talks with its leaders, if he decided it would serve U.S. interests. That was a marked change from the early days of George W. Bush's administration, when Iran recoiled angrily at being labeled part of an "axis of evil."

Clinton also had a lengthy meeting Tuesday with her Russian counterpart, Sergei Lavrov — her second since the March 6 meeting in Geneva to discuss a range of issues. Afterward, in an interview with NBC News, Clinton indicated that there would be a positive response to the meeting Wednesday between President Obama and Russia's President Medvedvev in London.

"We are looking to put out some statements that are quite substantive about the areas that we have discussed — we have been working with the Russians on an action plan to do followup to the meeting between our presidents. There is an enormous amt of work that has been undertaken by the state dept and the white house -

Asked if there is flexibility on missile defense, Clinton said they have made it clear from the beginning that if there is less of a threat from Iran, there would be less of a need for missile defense.

"We believe that this is an opportunity for the Russians and the Americans to work together — and the presidents will have a lot more to say about this tomorrow," she said.
Talking with the Taliban
Organizers of Tuesday's conference called it a success merely for the range of nations and organizations attending. Clinton and other diplomats pledged support for the fragile government of Afghan President Hamid Karzai, but avoided the argument over fighting troops that had put the United States at odds with some NATO allies.

This week's NATO summit meeting is not expected to raise significant numbers of fighting forces, despite Obama's decision to add some 21,000 U.S. troops before the end of summer.

Karzai and Clinton said Afghanistan would welcome Taliban fighters who embrace peace, reject al-Qaida and pledge to abide by the Afghan constitution.

Clinton said most Taliban fighters have allied with anti-government forces "out of desperation" rather than commitment, in a country that has barely made inroads against poverty and lack of development.

"They should be offered an honorable form of reconciliation and reintegration into a peaceful society" if they abandon violence and break with al-Qaida, she said.

Akhundzadeh was critical of Obama's plan to add U.S. troops, saying the money they cost would be better spent on building Afghanistan's own forces. But he added that "Iran is fully prepared to participate in the projects aimed at combating drug trafficking and the plans in line with developing and reconstructing Afghanistan."

In a closing statement, the conference agreed to promote good governance and stronger institutions in Afghanistan while generating economic growth and strengthening security.